793
FXUS63 KFGF 122336
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
636 PM CDT Mon Aug 12 2024

.KEY MESSAGES...

Thunderstorm chances return Tuesday night and continue through
Thursday. There is a less than 5 percent chance for isolated
severe impacts in the western Devils Lake Basin Wednesday.
Better chances (up to 15 to 20 percent) of locally heavy
rainfall during the period.

&&

.UPDATE...
Issued at 631 PM CDT Mon Aug 12 2024

Afternoon cumulus will continue to erode and with high pressure
in control we`ll see clear skies overnight with light winds.
Some morning low lying ground fog is possible in the typical
spots but impacts are not expected.

&&

.DISCUSSION...
Issued at 251 PM CDT Mon Aug 12 2024

Cumulus has grown tall enough to produce a few sprinkles just
north of Upper Red Lake, and will continue to get some isolated
weak convective activity in that area through sunset. Impacts
are nil. Upper ridging builds into the Plains tonight,
amplifying over the region tomorrow. One more quiet day is in
store as highs Tuesday climb to around 80 degrees, with some
increasing southeasterly winds as surface troughing develops to
our west.

For the system coming out Tuesday night into Thursday...there is
decent agreement on the overall pattern but still some
differences in the specifics. There should be good moisture
advection ahead of the system with southeasterly winds, and a
lead shortwave could bring some precipitation into our western
counties as early as Tuesday night. Better chances as the main
trough begins to move into the Western Plains Wednesday.
Deterministic CAPE values have swung back towards unimpressive,
but machine learning has some low probabilities of severe
impacts and ensemble probabilities of thunder are up around 33
percent for Wednesday night for our northwestern counties. Think
chances for any severe out in the far western Devils Lake Basin
are less than 5 percent, but can`t completely rule it out. Some
decent rainfall Wednesday night into Thursday as the trough
comes eastward into the midwest. R and M climate as well as the
ECMWF extreme forecast index show a wet signal going into
Thursday, and there is a 15 to 20 percent chance for 2 inches or
more over portions of our CWA during that 48 hour period. Not
going to hoist a flood watch or anything, but may have to watch
for some locally heavy rain as we head into the mid-week period.

Friday into Monday, northwesterly flow aloft sets up as the main
upper trough moves into the Great Lakes. There will be several
weak embedded shortwaves, mainly around Sunday, although
predictability is low. Temperatures should be fairly close to
seasonal averages.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 631 PM CDT Mon Aug 12 2024

Another VFR day is forecast tomorrow with SE winds developing
after light and variable overnight. Speeds will be around 10
kts with a few afternoon gusts to 20kts in the valley and DVL
possible.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

UPDATE...JK
DISCUSSION...JR
AVIATION...JK